Change users to roaming, Admin doesn’t like

One Domino server, one domain. Server is at 6.0.1, clients at 6.0.1 multi-user, database designs upgraded. Created a new roaming user, everything went well. When trying to change existing users to roaming get

06/03/2003 12:00:11 Admin Process: Searching Administration Requests database

06/03/2003 12:00:11 Error connecting to server name/NAME: The remote server is not a known TCP/IP host.

06/03/2003 12:00:11 Received the error - The remote server is not a known TCP/IP host. - connecting to name/NAME.

06/03/2003 12:00:11 Admin Process: Received the following error performing a Update Roaming User State in Person Record request on User Name/NAME. Received the error - The remote server is not a known TCP/IP host. - connecting to name/NAME. Will try to process this request again at 06/03/2003 12:01:11.

All other admin requests go okay.

Any ideas?